1. Field of the Invention
The present invention relates to technology for supporting design of a harness. The invention relates particularly to technology for realizing efficient harness design, such as installation position of a harness and design of a harness for its manufacturing, at designing and developing apparatus (for example, printers, automobiles, machine tools, industrial robots, and so on) in which a harness is incorporated. The “harness” in the present invention includes flexible and pliable belt-like and line-like members and bundles of such members, such as wiring incorporated in apparatus, cables, wires, piping and rubber hoses. The present invention is applied to placement design of such members.
2. Description of the Related Art
Generally speaking, when apparatus, such as printers, automobiles, machine tools, and industrial robots, in which harnesses are incorporated are designed, both the mechanical and electrical systems of the apparatus are designed to some extent, and then, harnesses which are placed between components forming the apparatus are designed, and installing positions and placement positions of the harnesses are determined.
This is because what kind of wiring should be placed where in the apparatus cannot be determined until design of the mechanical and electrical systems are completed to some extent, and for this reason, design of harnesses tends to be left until later. In reality, a harness is actually incorporated in a product prototype to adjust the length of the harness, so that problems related to the harness are not revealed quite a late stage.
Recently, a system has been developed in which a three-dimensional model designed by a three-dimensional CAD (Computer Aided Design) is used in placement design of a harness, to find problems of the harness as much as possible during the design process. The following are typical systems:                (1) “Embassy”: Linius Corp.        (2) “Cabling Designer”: Zuken lnc.        (3) “I-DEAS Harness Design”: EDS Corp.        
In these systems, three dimensional models of harnesses are designed on a three-dimensional CAD or using CAD data.
However, since three-dimensional CAD data can only express static assembly conditions, the above systems cannot verify problems of harnesses relating to motion of movable mechanical components.
More specifically, the following problems are considerable in an apparatus in which a harness is incorporated. A harness placed near a door is caught in the door when the door opens/closes; a harness which is linked to a linear mechanism is too short to follow motion of the linear mechanism; a harness which is linked to a rotational mechanism interferes with adjacent mechanical components. At design of a harness, verification needs to be performed to check that the above problems do not occur, which verification cannot be realized in the above systems.
In addition, since harness models designed on a three-dimensional CAD are solid models, whose calculation is time-consuming, they present problems in operability. In particular, in the above “EMbassy”, data written in VRML (Virtual Reality Modeling Language) is treated, and use of such data raises a problem of increasing display processing time.
With the foregoing problems in view, an object of the present invention is to make it possible to check motion of a harness in real time at harness design, without increasing the amount of processing, thereby providing an environment in which dynamic verification of harness design is available, and realizing efficient harness design.